The first thing to do is replace all the electrolytic capacitors. Some will
be bad by now and most will be marginal. A kit exists for this task.
You can also connect a signal generator to the tape input and an osicilloscope
to probe the signal path and check where the signal gets distorted but
it may not be one single component, rather a combination of more aged capacitors.
The scope will tell.

Martin

Hi Bart

Maybe I'm not reading your message correctly but it sounds to me that you have a problem with the signal that is being presented to the Tape input socket and not with the Beomaster 1900 itself.  Could you please explain what you have got connected to the Tape input socket.  If it is a tape deck unit of some sort, could your problem be related to the tape drive and not the BM1900?  My first step would be to change the input device and see if the distortion problem persists.  The fact that the radio and phono reproductions are OK seems to infer that the BM1900 amplifiers are OK and thereafter, there isn't too much that can go wrong in the Tape preamp part of the circuit. 

Regards

Geoff

No, the input signal is definitely not the problem. The input signal comes from a cd player which was always connected to this input and played fine before. When I connect this cd player to the phono input the sound is perfect. Every other device I connect to the tape input gives the same distorted sound.

Martin, where can I order this cap kit?

Sounds strange that your CD player plays fine through the Phono input ? The phono input has a built-in RIAA preamp so should
definitely NOT sound OK together with a normal CD player. Maybe you can check your CD player using a different amplifier, just to
rule out the CD player completely ?

You have a PM regarding capacitor kit, check your inbox in the extreme top right corner of this page.

Martin

Haha, I should have expected this comment.

I have made a slight modification to my Beomaster 🙂.  I have made a bypass of the RIAA pre-amp so that I can connect my DVD player. So the phono input of my Beomaster has the same characteristics as the tape input.

I have a how-to guide of this modification if someone's interested.